Space radio telescope

RadioAstron successfully blasted into orbit from Baikonur at 6.31 am local time on Monday 18. When it reaches an orbit that will extend almost as far as the moon, the RadioAstron mission will sync up with radio antennas on the ground, effectively forming the biggest telescope yet built, with a “dish” spanning almost 30 times the Earth’s diameter.

RadioAstron’s roots extend back more than three decades, but the mission lost momentum when the Soviet Union collapsed in 1991. “For 20 years it was always five years away,” says collaborator Ken Kellermann of the National Radio Astronomy Observatory in Charlottesville, Virginia.

Space radio telescope

Now, at long last, the spacecraft is poised to launch from Kazakhstan’s Baikonur cosmodrome at 0231 GMT on Monday.

At 10 metres, RadioAstron’s antenna is small compared to Earth’s largest radio telescopes, which span 100 metres or more. But when its signals are combined with those of telescopes on the ground – a technique called interferometry – the resulting observations are as sharp as those produced by a single telescope with a dish as wide as the maximum distance between the component antennas.